1http://igs.org IGS Workshop, 23-27 Jun. 2014, Pasadena

Preparing for the Future –The IGS in a Multi-GNSS World

O. Montenbruck

DLR/GSOC

2http://igs.org IGS Workshop, 23-27 Jun. 2014, Pasadena

… a federation of more than 200 institutions and organizations worldwide

… a Service of the International Association of Geodesy (IAG) founded in 1994

… operational since more than 20 years

... the premier source of the highest-quality GNSS data, products, and related standards and conventions

... in support of many applications that benefit the scientific community and society

… following an open data policy

… open to everybody to participate

The International GNSS Service is …

3http://igs.org IGS Workshop, 23-27 Jun. 2014, Pasadena

The Changing World of Satellite Navigation

• Two legacy systems, four new constellations,numerous SBAS satellites

• Inflationary increase in frequencies and signals

• Need for active investment into• Infrastructure• Algorithms & tools• Services

to maintain IGS „gold standard“ and to enable fullexploitation of new capabilities in science and engineering

(Credit: D. Turner, ION-GNSS-2010)

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The Good Old Days …

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System Blocks Signals Sats*)

GPS IIAIIR-A/BIIR-MIIF

L1 C/A, L1/L2 P(Y)L1 C/A, L1/L2 P(Y)

7127

5(+1)

GLONASS M L1/L2 C/A + P 24

*) Status May 2014; brackets indicate satellites not yet declared healthy/operational

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… and Today‘s „System of Systems”System Blocks Signals Sats*)

GPS IIAIIR-A/BIIR-MIIF

L1 C/A, L1/L2 P(Y)L1 C/A, L1/L2 P(Y)+L2C+L5

7127

5(+1)

GLONASS MK

L1/L2 C/A + P+L3

24(1)

BeiDou GEOIGSOMEO

B1, B2, B3B1, B2, B3B1, B2, B3

554

Galileo IOV E1, (E6), E5a/b/ab (4)QZSS IGSO L1 C/A, L1C, SAIF

L2C, E6 LEX, L51

IRNSS IGSO L5, S (2)

*) Status May 2014; brackets indicate satellites not yet declared healthy/operational

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Multi-GNSS Benefits – Visible Satellites

• More signals in space• Already ~40 satellites in Asia

• Improved atmospheric sounding• 3D tomography• Separation of height and tropo

• Improved PPP • Faster convergence• Faster ambiguity resolution• Increased robustness

(Trimble)

(G.Elgered)

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Multi-GNSS Benefits – PPP

(K. de Jong, Fugro)

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Multi-GNSS Benefits – Improved Signals

• Unencrypted signals on multiple frequencies

• 2-frequency radio-occultationsup to low tangent altitudes

• Reduced susceptibility to scintillation

• Advanced signal structures• Reduced multipath sensitivity• Very low code noise (AltBOC)

(PPP, GNSS-R) • Pilot-only signals (weak signal

tracking for RO)

(G.Elgered/J.Wickert)

(H. T. Diessengo, InsideGNSS 2012/09)

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Multi-GNSS Benefits – Clocks

• Highly stable clocks• Constrained POD• Discover orbit modeling

deficiencies• Improved real-time services• Improved kinematic PPP

PHM

PHM (ESA)

(Hackel et al., GPS Solutions, DOI 10.1007/s10291-013-0361-5)

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Multi-GNSS Benefits – Diversity

• Different • Satellites• Orbital periods• Orbital planes

• Reveal orbit modeling errors(SLR, SRP)

• Avoid GPS 24h commensurability• Product interval = 2x orbital period

• Provide improved EOP and geocenter observabitiy

GPS/GLO geocenter (Meindl et al.)

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Multi-GNSS Experiment (MGEX)

• Multi-GNSS Experiment (MGEX)• MGEX call-for-participation released mid-2011 (ongoing)• Steered by Multi-GNSS Working Group (MG WG)

• Some 30 contributing agencies from 20 countries• About 110 stations worldwide, mostly real-time

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MGEX Products

• Initial Precise Orbit and Clock Products• Galileo• QZSS• BeiDou

• Prototype Differential Code Bias Product• Cumulative Broadcast Ephemerides

• See Session PY07 for further details

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Multi-GNSS Challenges – Technical

• Characterization of new signals and equipment• Noise and multipath• Biases• Phase centers

• Characterization of new satellites• Attitude• Solar Radiation Pressure• Phase centers

• Modeling quality of new constellations must match orexceed GPS to take full advantage of Multi-GNSS

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Multi-GNSS Challenges – Organizational

• Don‘t let MGEX become a „parallel universe“• Unification of IGS legacy and MGEX networks

• Needs forceful transition to RINEX3 and single data holding• Needs (new?) tools for format conversion and quality control

• Standardization• Characterize new GNSSs• Tease system providers for information• Define and document processing conventions

• Integration of new systems into legacy analysis centersoftware and processes

• Tolerate multi-GNSS observations/products in all processes• Process multi-GNSS data (individual ACs, combination)

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Multi-GNSS Challenges – Workforce

• IGS is already working at its limits• No staff for multi-GNSS work• No staff for s/w development• New services (real-time) bind resorces

• Working groups and ACs still (too) focussed on legacyGPS/GLO work

• Review IGS goals and priorities• Legacy service• Real-time• Multi-GNSS• Monitoring

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Recruit New Workforce!

(Wikimedia)

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Multi-GNSS Challenges – Competition

• IGS no longer leads the crowd• Wake-up (or fall behind)

• GNSS industry has taken over• „Yes we can“• Proprietary networks (homogeneous, global real-time) • (Near-)real-time orbit and clock determination for GAL, BDS• High-performance PPP services

• Booming iGMAS• 8 analysis centers for multi-GNSS processing and monitoring

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Preparing for the Future

• New constellations will be operational by 2020

• Proposed steps• Adapt ANTEX, RINEX, SP3 („now“)• RINEX3/multi-GNSS Quality Control Tools (end 2014)• RINEX3 transition and unified data archive (mid 2015)• Multi-GNSS product standards (end 2014)• Multi-GNSS combination (end 2015)• Multi-GNSS pilot project (mid 2016)

• Align IGS scope and service portfolio with• Available resources• Changed environment (industrial/governmental services)• IGS role as an IAG service (science, geodesy)